Solvatten is a dual water treatment and solar water heating system that is tackling climate change and improving lives in Kenya’s urban slums. The device harnesses the power of the sun to treat and heat water, reducing the need to heat and boil water by burning firewood or charcoal. The units are capable of rendering highly contaminated water drinkable in a few hours, provided there is sufficient sunlight. Solvatten Solar Safe Water Heater improves health, increases renewable energy, reduces deforestation, addresses climate change and gives access to safe water, while lifting people out of poverty.
Key facts
- 2,592 Solvatten systems have been distributed and sold at a subsidized price in Kenya, benefitting 12,900 people in Nairobi’s urban slums
- 22,000 tonnes of greenhouse gas emissions have been avoided in Nairobi’s urban slums after four years of Solvatten use
- Almost 62 million litres of water have been treated since 2012
- More than 40,000 Solvatten systems are used daily by more than 200,000 people around the world
The problem
Families in Sub-Saharan Africa typically heat and boil their water by burning firewood and charcoal. Not only is this time consuming and expensive, it causes harmful indoor air pollution and releases greenhouse gas emissions. The high dependence on firewood and charcoal by a large percentage of the population is a major cause of deforestation in Kenya.
The solution
Swedish inventor Petra Wadstrom created the Solvatten system to bring portable water treatment and solar water heating to people in developing countries. Solvatten addresses poverty-related health issues that are connected to energy scarcity and poor water quality.
By harnessing the energy of the sun, the system ensures that the water is safe to use. A combination of UV rays and heat warms and eliminates all pathogenic material in 10 litres of water within 2-3 hours, allowing for multiple batches of water to be treated in a given day. The system is maintenance free and can be used more than seven years.
Helping the planet
The solar technology reduces the need to heat and boil water by burning firewood or charcoal. This leads to reduced deforestation, reduced burning of solid fuels, and consequently reduced emissions, as well as reduced fuel expenses for the urban poor. One year of using a Solvatten unit saves 5-6 mid-size trees.
By using solar energy instead of charcoal to heat and purify water, the Solvatten project in the Kenyan urban slum saves up to 6,000 tonnes of CO2 emissions every year. After four years of Solvatten use, 22,000 tonnes of greenhouse gas emissions have been avoided.
The significance of efficiency
Energy efficiency is the most effective tool to reduce energy sector emissions and contribute to limiting global warming to less than 2 degrees centigrade. The Solvatten technology makes resource use more efficient and provides the technology needed to refine that resource for use. In this case, the Solvatten technology purifies and heats water, directly improving energy and water efficiency.
Considering the efficiency factors, Solvatten should be valued not only based on the services that it brings, but also on the savings and ease of use that it entails. Moreover, even if there is infrastructure for water and energy available, Solvatten can support an under-sized electrical grid and water distribution.
Helping people
By ensuring access to safe and heated water the technology has increased the urban poor’s resilience to the effects of climate change, such as droughts and floods, and reduced their vulnerability to water-borne diseases. Both droughts and floods reduce water quality, which facilitates the transmission of water-borne diseases.
In this case, the Solvatten units were distributed and sold at a subsidized price of USD 15 for the end-user, generating a profit of USD 3 for the seller. The Nordic Climate Facility subsidized the units at a cost of 66% of the total market value, reducing the up-front burden. Use of Solvatten significantly reduces the amount of money the urban poor spends on alternative fuel sources (wood or charcoal). On average, users have been able to reduce their energy costs by half (savings of 11-12 USD per month).
Solvatten increases safety for women and girls by freeing up time for chores, such as collecting water and wood for cooking and boiling that typically fall on women and girls. Solvatten enables women and girls to focus on productive activities and school. According to a Solvatten survey, 66% of respondents said that absenteeism from school and jobs was significantly reduced after the inception of Solvatten.
Spillover effect
Solvatten aims to make health, environmental and economic benefits accessible to as many people as possible. The technology is available for the UN system, NGOs, governments and others to insure that families have a tool that brings heated and safe water to improve daily life. Solvatten contributes to reaching all of the 17 Sustainable Development Goals. Solvatten is exploring the possibility of scaling up the project to expand not only in Nairobi’s slums but in other parts of Kenya too. The goal is to reach millions of people living without access to electricity and safe water.
More than 800 million households worldwide currently use solid fuels. For these households living in sunny conditions, CO2 emissions could be reduced by 1 tonne per year if they reduced heating/boiling with solid fuels by using Solvatten.
Solvatten is highly replicable as the project methodology and process are successful and sound and can be replicated to other cities in other countries.
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